President Donald Trump said the U.S. will impose an additional 10% tariff on any countries aligning themselves with the "Anti-American policies" of the BRICS group of developing nations, whose leaders kicked off a summit in Brazil on Sunday.

Brazil is playing host to a summit of the BRICS bloc of developing economies Sunday and Monday during which pressing topics like Israel's attack on

The 11 emerging nations -- including Brazil, Russia, India, China and South Africa -- account for about half the world's population and 40 percent of global economic output.